The intent is that this software and documentation ("Project") should be treated as if it is licensed under the license associated with the Project ("License") in the LICENSE.md file. However, because we are the United States (U.S.) Federal Government, it's not that simple.
The portions of this Project written by United States (U.S.) Federal government employees within the scope of their federal employment are ineligible for copyright protection in the U.S.; this is generally understood to mean that these portions of the Project are placed in the public domain.
In countries where copyright protection is available (which does not include the U.S.), contributions made by U.S. Federal government employees are released under the License. Merged contributions from private contributors are released under the License.